Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Dec 4th, 2013–Dec 5th, 2013

Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.

Regions

Little Yoho.

10-20 cm was received in the forecast area earlier in the week, with the greatest amounts in the Eastern part of the region. Cold temperatures will remain and expect a gradual weakening of the snowpack support.

Weather Forecast

The alpine temperatures will dip to -30 by Friday, but become slightly warmer by the weekend to -20C for a high. Winds will remain light from the North. The Arctic high pressure will be in the region for the next several days.

Snowpack Summary

10-15 cm fell with moderate- strong North winds as the Arctic air moved in 2 days ago. Some reverse loading of slopes may have created some new windslabs in the alpine. There is 65-85 cm at our treeline study plots and some mid-pack support for skiing. Field tests still show failures on the Oct 27 crust where it exists or on the basal facets.

Avalanche Summary

In the last 24 hours, a size 2 avalanche occurred on a NW aspect of Copper Mountain, just west of Banff, at about 2350 m. It started as a point release which then triggered a 80 m wide slab that failed near ground, down 100-150 cm.

Confidence

Problems

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.